Here’s what we know so far about the shooting.
In the past, cannonballs have been used by police and military in the UK to mark their location or to signal a threat to others.
The device was first used in 1857 during the Civil War and was originally used to mark the position of a cannon.
It was later used to indicate the position in relation to the city in which it was fired.
In 2018, the British Army used a cannon ball to mark a military encampment, which it then used to target a military target in 2020.
According to the National Police Chiefs Council, a single cannonball can fire a projectile up to 1,500 metres (5,800ft) in length.
In total, a cannon has a range of over 10,000km (6,500 miles) in the air.
In 2019, the Metropolitan Police launched a pilot project with a cannon to mark police stations, with the aim of reducing crime.
The police used the cannon to fire at the top of the tower of St James’s Gate in south London to show officers the area’s crime problem.
After the shooting, the cannonball was returned to its home on the Thames in 2021, but it was used again for another three months in 2018.
The gun is now being used to protect the royal palaces in Buckingham Palace and the Houses of Parliament.